Mankind's ability to control the earth's vegetation has been a key focus of civilization. Agriculturalists and horticulturalists have not only devoted their time and energy to the study of increasing plant yields and vitality, providing drought and insect resistance, but also to providing plants with resistance to the periodic exposure to unusually cold temperature conditions—conditions that are outside the control of man.
Plants have evolved to be compatible with their native environment. However, people have always sought to adapt and enjoy plants outside of their native areas, for example, as ornamental decoration, as landscaping, or a food source. Man has therefore developed methods and techniques that allow plants to thrive in locations that are well outside the climatic zones where a plant naturally occurs. For example, greenhouses allow for controlled germination and protected early growth of plants therefore increasing their chances of long term survival. But once outside the control of these special conditions, the plant becomes susceptible to conditions that can be unnatural to the species or to conditions to which the species is ill adapted. This is especially true for ornamental plants such as palms that have become popular both as additions to décor, but that are also cultivated by a growing number of people as house plants, patio plants, and as landscape additions. Therefore, once transplanted or otherwise outside the protection of a green house, for example, in a storage area before being sold to a consumer, the sudden onset of cold temperatures beyond those to which the plant has naturally adapted, can cause injury or death to the plant.
As a guide to horticulturists, the United States Department of Agriculture has developed Plant Hardiness Zone maps for plants based on the average annual minimum temperature a given area experiences. Although these Zones do not take soil, rainfall, and other variables into consideration, they are extremely useful because winter low temperatures are the most significant environmental factor governing plant hardiness. Although developed for use in the United States, these same Zone designations are now used worldwide to classify areas into Hardiness Zones and to classify plant species on the basis of their Zone Hardiness.
USDA ZoneAverage Annual Minimum Temperature (° C.)1−45.6 and colder2−40.0 to −45.53−34.5 to −39.94−28.9 to −34.45−23.4 to −28.86−17.8 to −23.37−12.3 to −17.78 −6.7 to −12.29−1.2 to −6.610 4.4 to −1.11110.0 to 5.5 Most of the continental United States and Eurasia are included in Zones 2 through 10. For example, if a plant is classified as hardy from Zone 5 through Zone 7, it means that it will likely grow well in Zones 5, 6, and 7, and that winter minimum temperatures much colder than the norm in Zone 5 could cause damage and for mortality. Importantly, winter care practices and technologies can extend the effective USDA range of plant species.
Although some plants can slowly adapt to low temperature conditions, the risk of losing large established plants due to frost/freeze conditions is of concern to both those who cultivate and sell plants, as well as to those who grow and nurture plants for their own personal use. In addition, fruit trees are especially susceptible to sudden frost/freeze events. The loss of a fruit crop or a major part of the foliage of fruit trees has a far reaching economic impact.
There is therefore a need for methods and compositions for protecting plants across all species against the sudden and damaging effects of cold weather conditions. The present disclosure meets these, as well as other, needs.